One of the necessities of life is shelter and as a result building construction has traditionally been an enormous and important industry. However, the basic construction method of building a timber framed dwelling has changed relatively little over the many years it has been employed. Changes may take the form of improvements in the tools used, such as pneumatic nail guns replacing the traditional hammer and nail. But in general, substantially the same wood-product based materials and labor intensive timber frame construction dominate the field of building. Consequentially, newly constructed timber framed structures offer only slight structural improvements over structures built years before.
For many decades there was no real impetus to the building industry to devise improvements. Energy and labor costs were stable and the natural resources from which wood-product based materials are derived were thought to be plentiful and nearly inexhaustible. In recent years however, an urgent need has been recognized for improvements to construction. The disadvantages of employing inefficient material and labor usage have become magnified due to the sharply increasing costs of labor, energy, and wood products. It has also become apparent in recent years that the excessive use of wood products may have severely detrimental environmental consequences.
Also, there are many instances where sturdy shelter is required but the construction of conventional timber frame structures is impracticable, such as during military operations, after a natural disaster, or the like. In these instances a fast, durable and easy to construct structure that provides adequate shelter is desirable. The alternatives have been to use tents or prefabricated structures. Tents are usually a dismal failure because they provide only minimum protection from exposure and are prone to collapse. Prefabricated structures are also often inadequate because they are bulky and difficult to transport.
There is also an increasingly pressing demand for adequate shelter in areas where conventional construction is not feasible. Such is the case in poorer countries, or areas where wood-products are not readily available. Dwellings built in these areas are generally relatively primitive, labor intensive, and poorly constructed earthen or brick structures.
Traditional construction methods require many skilled and semi-skilled man hours. Special skills and tools are required for a multitude of construction steps. This has resulted in the specialization of workers in the construction trade. For example, it is common for separate crews with multitudes of workers to be employed to build the foundation, erect the decking and timber frame, hang the windows and doors, install the wiring, install the plumbing, hang the sheet-rock, paint the exterior walls, hang the exterior sheathing, hang the exterior finishing surface, paint the interior of the building, and various other specialized tasks.
The inefficiencies of such a process are numerous. Many workers must be employed and many man hours spent to complete all the conventional construction steps resulting in inflated building costs and excessive time to construct a building. Often a crew that is assigned to one of the construction steps is delayed and idled while the crew that performs the construction step that precedes it finishes its job behind schedule.
In addition to the excessive labor costs, a tremendous amount of wood-products are used to construct conventional buildings. It has been recognized that the overwhelming use of wood-products and the resulting deforestation to obtain these products is environmentally questionable. The cost of these wood-product based materials has continued to rise. The extensive use of wood products for structural members makes a structure susceptible to catastrophic failures due to termites, fire, rot, etc.
Another great disadvantage of conventional construction methods is the inefficient use of materials. Such methods produce a vast amount of scrap and waste material that must be carted away and disposed of in ever-dwindling land fill space. This inefficient use of construction materials is not only environmentally unsound, it also tends to greatly increases the cost of new construction.
Although skyrocketing heating and cooling costs have resulted in attempts at better insulated new construction, the traditional timber framed building still has poor insulating qualities. This drawback is inherent in traditional construction for a variety of reasons. For example, wood has a tendency to expand and contract in response to climatic changes. This causes warpage which creates gaps and makes drafts in traditionally constructed buildings inevitable. Modern ventilation, heating and cooling systems have been developed for the very efficient regulation of air quality and temperature in substantially air-tight structures. Unfortunately for traditionally constructed buildings, the efficiency of these systems depends on a substantially air-tight structure.
The electrical wiring of a conventionally constructed building has changed very little since it was first incorporated into new construction. There have been improvements in the wiring itself such as plastic sheathed wiring replacing metal sheath, but the method of installation remains virtually unchanged. Wiring is snaked through holes bored into the timber framed walls before the sheet-rock is hung. The wiring is terminated at locations where switches or outlets are desired. Among the disadvantages of this method is that there is no easy way to know where the wires are once the sheet-rock has been hung. This deficiency can have grave consequences to an unsuspecting homeowner who happens upon a live wire when drilling or hammering into a wall.
Generally, a conventional method of constructing a building begins with the construction of a foundation. To construct a conventional foundation requires many steps such as: (i) excavating an area for the foundation, (ii) pouring concrete for the foundation footing, (iii) constructing forms for a foundation wall on both sides of the foundation footing after the setting thereof, (iv) pouring concrete into the forms, (v) removing the forms after the concrete has set, (vi) carrying fill into the excavated area to form a base for pouring concrete for a concrete floor, (vii) pouring concrete for the concrete floor, and (viii) back filling around the perimeter of the foundation.
Conventional foundations are expensive to build especially because of the time and labor required in setting up construction forms, waiting for the cement to set, then removing the forms before moving on to the next step. These foundations are also prone to leaks due to ground water and storm runoff seeping through the inevitable cracks that form in the foundation's concrete walls and floor.
After the foundation has been constructed, the next step in a conventional building construction method is to build a conventional decking supported by the foundation. Next, it is preferable to lay out a covering over the conventional deck to act as a vapor barrier and provide insulation. Typically, this covering is a red-rosen paper or the like. Next a timber frame defining the exterior walls of the structure is erected. Individual segments of lumber are cut to size and nailed together to form a structural frame. Frames for windows and doors are included in the exterior wall frame. The next step in the construction of a conventional building is to hang the doors and windows in the frames built into the exterior wall frame. The next step is to erect timber frames defining the interior wall structures. As with the exterior wall frame, a multitude of individual segments of lumber are cut and nailed together to form a structural frame. Frames for doors are built into the interior wall frames and the interior doors are hung.
The next step in a conventional construction method is to construct a conventional roof supported by the exterior walls and load-bearing interior walls. Next a sheathing material, such as plywood, is hung on the outer side of the exterior wall frame to create the exterior wall surfaces of the building. The next step in a conventional construction method is known generally as roughing, to run electrical wiring and plumbing under and through the conventional decking and within the exterior wall frames and interior wall frames, terminating the electrical wires and pipes at roughly where switches, electrical outlets, and plumbing fixtures of the finished building will be. Next insulation is installed, such as sheets of fiberglass between the studs making up the exterior wall frames.
The next step in a conventional construction method is to hang an interior wall material such as sheet-rock on the inner side of the exterior wall frame and both sides of the interior wall frames to create the interior wall surfaces of the building. After the interior wall surfaces have been hung, the next step is to tape the joints between the sections of hung sheet-rock. Taping includes the steps of applying a paper tape to cover the joint and smoothing a thin layer of joint compound material over the tape, thus creating a smooth and continuous surface spanning the length of each interior wall.
While the inside work is being done, the outside finished surface of the building is secured to sheathing hung on the exterior walls. This outside surface is typically clap-board, brick-face, aluminum siding or the like. Finally, the interior and exterior surfaces are primed and painted and the scrap generated during the construction is hauled away.
Conventional construction methods have many drawbacks. Labor costs due to many man-hours and specialized crews, material costs, wastes generated, excessive use of limited natural resources, inherently poor insulation qualities of the structure, excessive time to construct, etc., make conventional construction methods inefficient at best. The wastes generated by conventional construction methods place an increasing burden on limited land fill space. The extensive use of wood products for framing lumber, sheathing material and the like by conventional construction methods results in a structure that is difficult to insulate and is prone to drafts and catastrophic failure.